Macro-algae or “seaweeds” are multicellular plants growing in salt or fresh water. They are often fast growing and can reach sizes of up to 60 m in length. They are classified into three broad groups based on their pigmentation: i) brown seaweed (Phaeophyceae); ii) red seaweed (Rhodophyceae) and iii) green seaweed (Chlorophyceae). Seaweeds are mainly utilized for the production of food and the extraction of hydrocolloids. Micro-algae are microscopic organisms that grow in salt or fresh water. The three most important classes of micro-algae in terms of abundance are the diatoms (Bacillariophyceae), the green algae (Chlorophyceae), and the golden algae (Chrysophyceae). The cyanobacteria (blue-green algae) (Cyanophyceae) are also referred to as micro-algae, this applies for example to Spirulina (Arthrospira platensis and A. maxima). Diatoms are the dominant life form in phytoplankton and probably represent the largest group of biomass producers on earth. It is estimated that more than 100,000 species exist. The cell walls of diatoms contain polymerised silica, and they often accumulate oils and chrysolaminarin. Green algae are especially abundant in fresh water. The main storage compound of these algae is starch, although oils can also be produced. The fresh water green algae Haematococcus pluvialis is commercially important as a source for astaxanthin, Chlorella vulgaris as a supplementary food product, and the halophilic algae Dunaliella species as a source of β-carotene. The golden algae are similar to the diatoms and produce oils and carbohydrates. The blue-green algae (cyanobacteria) are found in a variety of habitats and are often known for their toxic water polluting products.
Macro-Algae
Seaweeds or macro-algae belong to the lower plants, meaning that they do not have roots, stems and leaves. Instead they are composed of a thallus (leaf-like) and sometimes a stem and a foot. Some species have gas-filled structures to provide buoyancy. They are subdivided in three groups, the red, brown and green macro-algae.
In their natural environment, macro-algae grow on rocky substrates and form stable, multi-layered, perennial vegetation capturing almost all available photons. Due to the fact that seaweeds are fixed to their substrate, values for maximum productivity may be 10 times higher for a seaweed stand than for a plankton population, and can be as high as 1.8 kg C m−2 y−1. The maximum chlorophyll content is 3 g m−2 illuminated surface, corresponding to an algal biomass of about 10 kg m−2. The productivity of plankton is much lower because most of the photons are absorbed or scattered by abiotic particles, and the algae are so thinly distributed.
Commercial farming of seaweed has a long history, especially in Asia. The kelp Laminaria japonica is the most important with 4.2 Mio t cultivated mainly in China. Approximately 200 species of seaweeds are used worldwide, about 10 of which are intensively cultivated, such as the brown algae Laminaria japonica and Undaria pinnatifida, the red algae Porphyra, Eucheuma, Kappaphycus and Gracilaria, and the green algae Monostroma and Enteromorpha.
Several species having a range of specific requirements for their living environment appear to be especially suited for large-scale cultivation. These requirements are nutrients, salinity, temperature, light, depth, and currents. Factors that affect cultivation also include predation, growth of epiphytes, and pollution. An example is giant brown kelp (Macrocystis pyrifera), which has a high light absorptive capacity, and doubles its weight every six months. Tests in the open sea (off-shore) revealed a range of difficulties which included access, mooring, nutrient supply (by upwelling), and harvesting.
Micro-Algae
Micro-algae are microscopic photosynthetic organisms that are found in both marine and freshwater environments. Their photosynthetic mechanism is similar to landbased plants, but due to a simple cellular structure, and submerged in an aqueous environment where they have efficient access to water, CO2 and other nutrients, they are generally more efficient in converting solar energy into biomass.
These organisms constitute a polyphyletic and highly diverse group of prokaryotic (two divisions) and eukaryotic (nine divisions) organisms. The classification into divisions is based on various properties such as pigmentation, chemical nature of photosynthetic storage product, the organization of photosynthetic membranes and other morphological features. The most frequently used micro-algae are Cyanophyceae (blue-green algae), Chlorophyceae (green algae), Bacillariophyceae (including the diatoms) and Chrysophyceae (including golden algae). Many microalgae species are able to switch from phototrophic to heterotrophic growth. As heterotrophs, the algae rely on glucose or other utilizable carbon sources for carbon metabolism and energy. Some algae can also grow mixotrophically.
Micro-algae are applied as food and as live feed in aquaculture for production of bivalve molluscs, for juvenile stages of abalone, crustaceans and some fish species, and for zooplankton used in aquaculture food chains. Therapeutic supplements from micro-algae comprise an important market in which compounds such as β-carotene, astaxanthin, polyunsaturated fatty acid (PUFA) such as DHA and EPA and polysaccharides such as β-glucan dominate.
Exploitation of micro-algae for bioenergy generation (biodiesel, biomethane, biohydrogen), or combined applications for biofuels production and CO2-mitigation, by which CO2 is captured and sequestered, are under research.
Cyanobacterium (also known as blue-green algae, blue-green bacteria, and Cyanophyta) is a phylum of bacteria that obtain their energy through photosynthesis. The name “cyanobacteria” comes from the color of the bacteria. The ability of cyanobacteria to perform oxygenic photosynthesis is thought to have converted the early reducing atmosphere into an oxidizing one, which dramatically changed the composition of life forms on Earth by stimulating biodiversity and leading to the near-extinction of oxygen-intolerant organisms. According to endosymbiotic theory, chloroplasts in plants and eukaryotic algae have evolved from cyanobacteria via endosymbiosis. Some cyanobacteria are sold as food, notably Aphanizomenon flos-aquae and Arthrospira platensis (Spirulina). Recent Researches have also hinted at their possible application to the generation of Clean and Green Energy via converting sunlight directly into electricity. Currently efforts are underway to commercialize algae-based fuels such as diesel, gasoline and jet fuel.
Influenza
Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae, which can be further classified into influenzavirus A, B and C. The influenza A virus can be subdivided into different serotypes based on the hemagglutinin (HA) and neuraminidase (NA) proteins on the surface, wherein the serotypes of H1N1 and H3N2 commonly cause pandemics. The most common symptoms of the disease are chills, fever, sore throat, muscle pains, severe headache, coughing, weakness/fatigue and general discomfort, even includes bronchitis, pneumonia and encephalitis.
Hemagglutinin has two functions. Firstly, it allows the recognition of target vertebrate cells, accomplished through binding to the sialic acid-containing receptors on cell surface. Secondly, once bound hemagglutinin facilitates the entry of the viral genome into the target cells by causing the fusion of host endosomal membrane with the viral membrane. http://en.wikipedia.org/wiki/Hemagglutinin_%28influenza%29-cite_note-6 For target specificity, the viral hemagglutinin protein would be selectively cleaved by several human proteases to produce functional protein. In general influenzaviruses, the hemagglutinin can only be cleaved by proteases found in the throat and lungs, so that these viruses cannot infect other tissues. However, in highly virulent strains, such as H5N1, the hemagglutinin can be cleaved by a wide variety of proteases, allowing the virus to spread throughout the body. Neuraminidases, also called sialidases, catalyze the hydrolysis of terminal sialic acid residues from the newly formed virions and from the host cell receptors, and result in the releasing of newly formed virions.
Influenza A (H1N1) virus is a subtype of influenza A virus and was the most common cause of human influenza (flu). The 2009 flu pandemic was a global outbreak of a new strain of H1N1 influenza virus. The flu caused by H1N1 virus can be treated by Tamiflu or Relenza, which are belong to neuraminidase inhibitors. However, more and more Tamiflu-resistant virus strains have been identified clinically. According to the related studies, Tamiflu-resistant influenza A virus has been found that resistance is resulting from the H274Y mutation in neuraminidase (NA).
Influenza virus B is another type of Influenza virus. Influenza virus B sometimes causes regional outbreak and mild symptoms than influenza virus A, however, attention is required. Traditionally, the drug for treating influenza virus A is used to treat influenza virus B, but it is helpful for inhibiting influenza B outbreak by developing a specified drug.
Extraction Process from Algae
Diverse active compounds in cyanobacteria for inhibiting virus can be extracted by some known methods for extraction, however, which is restricted to its biological structures such as cell walls. To obtain inner active materials of cyanobacteria, their cell walls must be destroyed. Traditional methods for destroying cell walls include boiling, bead milling and ultrasonic vibration. All of these methods would generate heat that may influence activity of the active materials. Besides, organic solvent can be used to break cell walls. However, the biological activity and function of materials extracted by this method is totally different from the active materials of the present invention. Therefore, to effectively break the cell wall and obtain active materials in cyanobacteria is a problem needs to be solved in the related art.
U.S. Pat. No. 7,220,417 discloses a use of an extract of the alga Phaeodactylum, which is categorized as macro-algae, as a cosmetic agent promoting the proteasome activity of skin cells. The extract is produced by adding a solvent to soften alga Phaeodactylum at the room temperature, freezing the alga at −20° C.˜−40° C. for 1-7 days, and adding the solvent and heating. This patent is mainly used to extract macro-algae. Though the freezing is used, it cannot effectively break cell walls to obtain the active ingredients, so that a solvent and heating process is still required. Thus, the manufacture used in this patent is not identical to the present invention.
U.S. Pub No. 20090042801 is the prior application of the applicant, which discloses a pharmaceutical composition comprising C-phycocyanin, allophycocyanin, spirulina growth factor, and the mixture thereof. The composition is extracted by the method comprising the steps of: (a) adding hypotonic buffer solution to organic blue-green algae powder and mixing thoroughly; (b) incubating the mixture below room temperature overnight; (c) separating and purifying the mixture by a centrifuge; (d) collecting the suspending supernatant and detecting it by a spectrometer to determine ingredients and content; and (e) spray drying the supernatant; characterized in which low-temperature (0-18° C.) extraction is employed. However, the manufacture process is complicated and time-consuming. Due to a poor yield of active product obtained by longer and complicated manufacture process, applicants improve the previous manufacture process by low-temperature disintegration technology. Accordingly, not only previous complicated manufacture process can be simplified, but also activity and concentration of the extracted product can be significantly increased.
The cyanobacterial extract of the present invention is able to inhibit infection and replication of influenza A virus mutant and influenza B virus. Due to the urgent requirement of drugs against flu, the cyanobacterial extract of the present invention can be used as drugs to treat flu and prevent the pandemic.